It is most often novice buyers who tend to leave negative feedback without contacting sellers first, people who have a generally fearful view of the world or of new things and who see minor glitches as opportunities to "lash out" at "big business, big brother, mom & dad" and so on; it's somewhat socialized into the American way, the result of distant bureaucratic systems like the school system.
It takes people a while to find a comfort level on eBay which they may never have found before.
The thing I have always liked about eBay is that, on an individual basis, it reaffirms my basic trust in human nature, the impulse of individuals to do the right thing, to reach out in friendship -- pretty much the same way the internet has reaffirmed that.
There will always be little freaks out there; hopefully they will become socialized to larger global realities.
I don't know what recourse there might be for minimizing the effect of erroneous negative feedback, premature negative feedback.
I still do think that a two-way feedback system should still be in place -- I like it; it keeps me on my toes, as I said, as a seller and as a buyer -- and if that is not possible, then a system by which a buyer can earn one-way feedback, say after receiving 10 or 15 positive feedback ratings. That could be automated into the system easily enough, I think, and it would be a good compromise between eBay and sellers.
I haven't suggested it; I suppose they have trawlers out there reading boards on behalf of the larger organization.